Everything is simple at the highest levels of abstraction. It is the details of actually making it work that raise the complexity levels and/or kill you if you

Everything is simple at the highest levels of abstraction. It is the details of actually making it work that raise the complexity levels and/or kill you if you don't get them right. Remember: a decision that in the abstract with infinite thinking time is easy can be extremely stressful when it has to be made in seconds in real time and getting it slightly wrong will potentially cause a catastrophe. And ATC has to keep doing this throughout their entire work shift.